Due to the importance of parenting on a host of outcomes, a tremendous fund of information on the parenting behavior of mothers of both normal and deviant children has accrued over the past century. Yet, research on fathers, fatherhood, and how fathers parent their children is sorely lacking. The knowledge gap between fathers'parenting practices and behavior and the research base is most pronounced in the area of child psychopathology (Phares, 1996), the area where this information is possibly the most important. Children with attention-deficit hyperactivity disorder are one group effectively treated with behavioral parent training, but father involvement is typically lacking in such programs. Because parents who are consistent, self-confident, and affectionate in their approach to parenting raise socially competent children (McCord, 1991;Reid, Webster-Stratton, &Hammond, 2003), and poor parental monitoring and inconsistent or punitive discipline strategies predict a number of negative adolescent and adult outcomes (Frick &Loney, 1999;Loeber &Hay, 1997), engaging fathers in parent training has important implications for public health and the long term outcomes of children with ADHD. The present application aims to develop and evaluate a parenting program designed especially for fathers that aims to engage and retain them in treatment while also teaching evidence based strategies for improving the behavior of children with ADHD. The fathers program aims to integrate components from two existing manualized treatment programs commonly used with children with ADHD: the Community Parent Education program (COPE;Cunningham et al., 1998) and the summer treatment program (STP;Pelham et al., 1998). The specific aims of the application are to develop a manualized treatment for fathers and related program materials;investigate the efficacy of the novel parenting program for fathers to a control group in a small clinical trial;and investigate the efficacy of integrating the novel father-based intervention into a standard behavioral parent training program that includes mothers and fathers.